No mention if the lady was diabetic..... Even gestational diabetes can account for larger babies. It also does not say of she has this baby (or the other one naturally or C-section)
Also the "normal" weight baby looks quite tiny, most likely a 4.5 - 6 pounder. Might even be premie because of the feeding tube, and the oxygen saturation monitor on his/her ankle. I think this was on purpose to show how large the other one is. You know more shock value
Either way, he is a big baby, here is hoping he is healthy and does not end up being obese as a child or adult.